There are many applications in which flexible high-pressure thermoplastic hose is used for the transmission of volatile or combustible fluids. Since the materials from which hoses are generally manufactured (i.e., rubber or synthetic polymers) are essentially non-conductive, it is a common practice in these applications to incorporate an element of at least limited conductivity within the body of the hose to permit grounding of the hose and the dissipation of static electric charges. A typical application is a paint spray hose in which paints or lacquers are pumped through a flexible hose to a spray gun at relatively high pressures. In some recently developed commercial installations, the pressures may reach as much as 700 kg/cm.sup.2. The flow of fluid materials through the hose may cause static electric charges to build up which, if not discharged to ground, can lead to explosion of the volatile solvents or other paint vehicles.
To avoid the danger of explosion and fire when inflammable fluids are transmitted through thermoplastic hoses, it is conventional to incorporate a conductive element within the wall of the hose. In co-pending U.S. patent application Ser. No. 085,386 filed on Oct. 16, 1979, now abandoned, having a common assignee and which is incorporated herein by reference, there is disclosed a grounding element in the form of a tape of limited conductivity. The tape is made from a heat sinterable plastic filled with finely divided carbon particles and, in a preferred embodiment, is comprised of a sintered tape having a matrix of polytetrafluoroethylene filled with finely divided carbon black. An anti-static element of this sort is quite useful since it has sufficient conductivity to drain static electric charges and sufficient strength to withstand abuse while exceeding the industry standard for pressure pulses without loss of continuity. It is, of course, necessary to connect the anti-static element to a ground and this conventionally accomplished bringing the anti-static metal fitting element into contact with a fitting which, in turn, can readily be grounded. It has been a recurring problem to find a simple means for insuring electrical contact between the conductive element and the fitting, particularly considering the fact that the conductive member may pull back under the cover of the hose when the hose is cut to length to attach fittings.